PDP1 and COVID-19: Furthermore, the Kaplan-Meier plots (Fig. 2) and cox regression analyses did not confirm any significant difference in the PDP-free (Hazard Ratio [HR] [95% CI]: 0.46 [0.12, 1.73], P = 0.25) and relapse-free (HR [95% CI]: 0.69 [0.31, 1.53], P = 0.36) survivlas between the pre- and post-COVID-19 periods.